We learned about a birth control vaccine called PZP, porcine zona pellucid, that can be darted into the mares. Dr. Jay Kirkpatrick and his team at The Science and Conservation Center in Billings Montana have been instrumental in helping us. You must be licensed and trained to use the dart gun and vaccine at the center. So they referred us to a lovely lady Deniz Bolbol from the American Wild Horse Preservation Campaign. She lives south of San Francisco, and generously drove all the way up here to dart our two mares on October 11th. Here she is preparing to dart one of the mares.
It all went very smoothly. We fed the small herd and the girls were darted while they were eating and there was no big fuss on their part! They will get 2 more booster darts in the spring and next summer. After that they will be darted with the vaccine once a year for 5 years. At which point they should be able to produce their own birth control. The success rate is 90% and since these ladies are over 20 I expect that there will no more babies after these two foals are born. They can be darted any time during their cycle.
Mike Dinning, our good friend and pinto assistant, went to Montana for a week to participate in the training. He is now licensed and will be darting the mares in the future. We also plan to dart the mares on this property just as a precaution. These mares live with geldings but if Thunder should by accident get over here, we would be increasing this herd!
Here is a list of the wild horses that PZP is helping:
The vaccine has been used successfully to manage the wild horse population of Assateague Island National Seashore under the authority of the National Park Service (NPS). being treated on Cape Lookout National Seashore for the NPS, on Carrot Island, for the Rachel Carson National Estuarine Reserve, and on Corolla Island, both
in NC, the Pryor Mountain and Little Book Cliff National Wild Horse Ranges, MT and CO, respectively, the McCullough Peaks wild horse range in WY, on many areas of Nevada, Utah, Oregon for the Bureau of Land Management (BLM), on the Carson National Forest, for the National Forest Service, on several wild horse sanctuaries, and on the Navaho and Pima/Maricopa Indian Reservations in NM and AZ. I
For more information including the science of the vaccine please check out THE SCIENCE AND CONSERVATION CENTER website AT http://www.sccpzp.org/
I am so grateful to Deniz and Dr. Kirkpatrick for all their help!! It is such a relief for the mares not to have future babies so they can quietly live out the rest of their lives without any responsibility. Plus I am delighted not to have more horses coming as we have plenty!
Deniz with the dart gun